The present invention relates to a vehicle wiper device, and more particularly to a wiper device for wiping an openable rear window and the installation method.
A typical station wagon or a hatchback has a rear door. Some such doors have openable windows that are opened independently from the rear door. A typical wiper device for wiping the window glass of such a rear door is directly attached to the window glass.
The wiper device has a relatively heavy actuator. When the window is shut, the glass may forcefully contact the rear door. This applies a relatively great force to the glass where the actuator is fixed. This can damage the glass. Manually opening and closing the window requires relatively great physical force. Also, if the actuator is attached to the glass, the wiring for supplying electricity to the motor in the actuator becomes complicated.
To solve these problems, a wiper device having an actuator attached to the rear door has been proposed. In this device, a wiper arm is pivotally supported by the rear window. When the rear window is closed, the wiper arm is coupled to the actuator.
The actuator is fixed to the rear door. A pivot disk is fixed to an output shaft of the actuator. The pivot disk is rotated within a predetermined angular range, and the direction of rotation alternates. The disk has a coupler hole, which is radially spaced from the axis of the output shaft. A pivot shaft is attached to the rear door through the shaft holder. When the rear window is closed, the axis of the pivot shaft needs to be aligned with the axis of the output shaft. The distal end of the pivot shaft extends to the rear and exterior of the vehicle. The wiper arm is fixed to the distal end of the pivot shaft. The distal end of the wiper arm is coupled to a wiper blade (not shown). The wiper blade wipes the surface of the rear window. The distal end of the pivot shaft (the end extending to the actuator) is coupled to the crank lever. A coupler pin is located at the distal end of the crank lever.
When the rear window is closed, the coupler pin enters the coupler hole in the disk, which couples the crank lever to the disk. When the actuator pivots the disk, the crank lever pivots integrally with the disk. The alternating rotation of the crank lever is transmitted to the wiper arm by the pivot shaft. Accordingly, the wiper arm pivots in an angular range that corresponds to the pivot range of the disk, which causes the wiper blade to wipe the surface of the rear window.
If the output shaft of the actuator is misaligned with the pivot shaft when the wiper device is installed to the vehicle, the axis of rotation of the pivot disc does not coincide with the pivot axis of the crank lever. This prevents smooth movement of the wiper device and causes the rotation angle of the disc to differ from the pivot angle of the crank lever. As a result, an error in the pivotal angle of the wiper arm occurs, and the path of the wiper blade may be different from that desired. Accordingly, the position of the actuator or that of the wiper device must be accurately adjusted to align the axes of the output shaft and the pivot shaft. This complicates installation of the wiper device.
An objective of the present invention is to provide a vehicle wiper device that is easily installed and prevents the output shaft from being misaligned from the pivot shaft and the method of installing the wiper device.
To achieve the above objective, the present invention provides a wiper device for wiping a window supported by a support. The wiper device is located between the window and the support. The window opens and closes an opening in the support. The device comprises an actuator attached to the support. The actuator has an output shaft and a first coupler member attached to the output shaft. The actuator pivots the first coupler member in a first angle range. A power transmission unit includes a shaft holder attached to the window, a pivot shaft supported by the shaft holder and a second coupler member attached to the pivot shaft. When the window is closed, the second coupler member is coupled to the first coupler member to transmit rotation of the output shaft to the pivot shaft. A wiper arm is attached to the pivot shaft. When the actuator is activated with the second coupler member coupled to the first coupler member, the wiper arm pivots in an angle range corresponding to the first angle range. When the wiper device is installed, a positioning mechanism provisionally fixes the position of the power transmission unit relative to the actuator such that the axis of the pivot shaft is aligned with the axis of the output shaft.
The present invention further provides a method of installing a wiper device. The method comprises: attaching an actuator to a support, wherein the actuator includes an output shaft and a first coupler member attached to the output shaft; attaching a shaft holder of a power transmission unit to a window, wherein the power transmission unit includes a pivot shaft supported by the shaft holder and a second coupler member attached to the pivot shaft, wherein rotation of the output shaft is transmitted to the pivot shaft when the second coupler member is coupled to the first coupler member; fixing the position of the power transmission unit relative to the actuator such that the axis of the pivot shaft is aligned with the axis of the output shaft prior to at least one of attaching the actuator to the support and attaching the shaft holder to the window; and releasing the power transmission unit relative to the actuator after the actuator is attached to the support and after the shaft holder is attached to the window.
The present invention further provides a method of installing a wiper device. The method comprises: attaching an actuator to a support, wherein the actuator includes an output shaft and a first coupler member attached to the output shaft; attaching a shaft holder of a power transmission unit to a window after attaching the actuator to the support, wherein the power transmission unit includes a pivot shaft supported by the shaft holder and a second coupler member attached to the pivot shaft, wherein rotation of the output shaft is transmitted to the pivot shaft when the second coupler member is coupled to the first coupler member; and fixing the position of the power transmission unit relative to the actuator such that the axis of the pivot shaft is aligned with the axis of the output shaft prior to at least attaching the shaft holder to the window, wherein the shaft holder moves toward the window and releases the fixation of the power transmission unit relative to the actuator when the shaft holder is attached to the window.